Working and ageing - Cedefop - Europa
Working and ageing - Cedefop - Europa
Working and ageing - Cedefop - Europa
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CHAPTER 5<br />
Cognitive <strong>ageing</strong> in older workers <strong>and</strong> its impact on lifelong learning 95<br />
hold as well as on the way information is stored <strong>and</strong> organised. A basic<br />
distinction is that between short-term <strong>and</strong> long-term memory. Short-term<br />
memory involves immediate recall of items, has a capacity of 7±2 items <strong>and</strong><br />
is commonly used when attempting to memorise a short list of items. While<br />
long-term memory involves permanent storage of information in an organised<br />
ʻmental lexiconʼ, it is unlimited in capacity <strong>and</strong> often described as a library of<br />
knowledge encoded <strong>and</strong> stored in a relevant <strong>and</strong> meaningful individual<br />
manner, to be recalled later. <strong>Working</strong> memory is a theoretical concept first<br />
described by (Atkinson <strong>and</strong> Shiffrin, 1968) that involves ability actively to hold<br />
relevant information to perform a complex task such as problem-solving <strong>and</strong><br />
reasoning. The working memory system (Baddeley, 1999) includes a central<br />
executive that organises sensory input with assistance of attentional<br />
mechanisms, a visuo-spatial sketchpad (for non-verbal information) <strong>and</strong> a<br />
phonological loop (for verbal information).<br />
Long-term memory is further separated into episodic, semantic <strong>and</strong><br />
procedural memories, which involve events, meanings <strong>and</strong> procedures<br />
respectively. Although long-term memory is unlimited most times healthy<br />
individuals fail to retrieve information accurately. Mnemonic strategies may<br />
reduce forgetting but memory failures are the rule rather than the exception<br />
in everyday situations. The reasons for forgetting have been extensively<br />
investigated due to the importance of memory in personal <strong>and</strong> professional<br />
environments. Most people in middle adulthood complain that they can not<br />
recall substantial information on processes, procedures <strong>and</strong> events <strong>and</strong> are<br />
forced to use reminders to improve their memories. The most important<br />
reasons for forgetting are:<br />
(a) encoding specificity (Thomson <strong>and</strong> Tulving, 1970);<br />
(b) decay (Woodworth, 1938);<br />
(c) lack of access because of emotional load or repressure (Baddeley, 1999);<br />
(d) interference (Barnes <strong>and</strong> Underwood, 1959);<br />
(e) amnesia (Baddeley, 1970).<br />
Given the importance of memory in daily activities, several authors have<br />
discussed memory deficits resulting from normal <strong>ageing</strong> (Gregoire <strong>and</strong><br />
Van der Linden, 1997). The studies yielded contradictory results. Table 5.1<br />
provides an overview of the main findings of more recent studies on memory<br />
<strong>and</strong> <strong>ageing</strong> in non-pathological individuals.<br />
From Table 5.1 it is clear there are substantial differences in results<br />
depending on age groups <strong>and</strong> the task used. In relation to short-term memory<br />
which involves immediate recall of short lists of digits there is small decline<br />
that accelerates after the age of 70. On the other h<strong>and</strong>, well-practiced tasks